Scraper



Oct. 1, 19 40. H. c. FRENCH SCRAPER Filed Dec. 9, 1958 2 Sheets-Sheet 1 Oct. 1, 1940.

H. C. FRENCH SCRAPER Filed Dec. 9. 1933 2 Sheets-Sheet? Patented Oct. 1, 1940 I UNITED STATES PATENT -OFFICE SCRAPER Henry C. French, Milwaukee, Wis., asslgnor to The Hell 00.,Milwaukee, Wia, a corporation of Wisconsin I Application December 9, 1938, Serial No. 244,762

14 Claims. (01.37-126) This invention relates generally to improvements in scraper assemblages of the type adapted to remove and carry quantities of earth from place to place and to dump the loads as desired, and relates more specifically to improvements in the construction and operation of the load confining aprons for road scrapers and the like.

Generally defined, an object of my. present invention is to provide an improved scraper apron structure and improved mechanism for manipulating such structures.

It.has heretofore been common practice in the manufacture of so-called dig and carry scrapers, to provide the load confining and carrying bowls with front and rear aprons which are cooperable respectively with the bowl to confine the loads therein and to effect removal thereof. The front load confining apron is ordinarily pivotally suspended from the opposite side walls of the bowl and is oscillatable about its suspension pivot, toward and away from the scraper blade carried by the front portion of the bowl bottom, by mechanism such as a hydraulic jack suspended from the front of the scraper frame. In these prior hydraulically actuated front apron assemblages, the plunger of the jack is ordinarily plvotally attached to the swinging forward portions of the front apron and no provision is made for lost motion or relative movement between the apron and the pivot pin, so that when the scrapers or the like, which is durable in construction and highly efficient in use.

A further object of the invention is to provide a simplified front apron structure for dig and carry scrapers, which will provide maximum clearance for material entering and leaving the load carrying bowl.

These and other objects of the present invention will be apparent from the following detailed description.

. A clear conception of an embodiment of the invention, and of the mode of constructing and of ion operating scraper aprons built in accordance with the improvement, may be had by referring to the drawings accompanying and forming a part of this specification, wherein like reference characters designate the same or similar parts in the various vie'ws.

Fig. 1 is a part sectional side elevation of a dig and carry scraper assemblage, showing the cuttinghlade embedded in the ground, the bowl partially loaded,.and the front apron lowered;

Fig. 2 is an enlarged part sectional inside or rear view of the front apron alone;

Fig. 3 is a similarly enlarged vertical section through the front apron, taken along the line 3-3 of .Fig. 2;

. Fig. 4 is a fragmentary part sectional side view of the portion of the scraper adjacent the cutting blade, showing this blade in action and the front apron elevated with the aid of the hoist alone, and

Fig. 5 is a view similar to that of Fig. 4, but showing the front apron additionally elevated to provide maximum space between the apron and the cutting blade.

; While the invention has been specifically applied to a particular type of dig and carry scraper assemblage having a load receiving bowl provided with relatively movable front and rear aprons, it is not the intention to thereby unnecessarily restrict the scope of the improvewent.

,Referring to the drawings, the load receiving and transporting scraper assemblage shown therein comprises in general, a main frame 8 which is swingably and transportably supported at its lower front portion upon a wheeled draft carriage 9,.and is providedwith rearwardly.extending laterally spaced side arms 10 rigidly interconnected at their front and rear ends by transverse beams; a load carrying bowl H having parallel side walls l2 rigidly suspended from the side arms Ill, and a bottom l3 rigidly connecting the lower extremities of the side walls l2; a cutting blade I attached to the front edge of the bowl bottom l3; a front apron l5 having relatively long side arms l6 pivotally suspended from the side walls I2 of the bowl I l and being operable by means of a hydraulic jack I! which is pivotally suspended from cars It rigidly associated with the front transverse beam of the mai frame 8; a rear ejector apron l9 movable itudinally within the bowl ll between the side walls I! and over the bottom I3; actuating levers 20 for the rear apron I5, pivotally suspended from the rear transverse beam of the 5 main frame 8, and being operable by means of a second hydraulic jack 2!; an auxiliary frame 22 having its front end pivotally connected to the rear lower portion of the bowl II, and. its rear end pivotally suspended from rear transporting wheels 23; and a third hydraulic jack 24 coacting with the frames 8, 22, to relatively move the same so as to raise and lower the blade I4.

The main frame 8 and bowl II are preferably constructed of relatively stiff. sheet metal plates, welded or otherwise rigidly interconnected so as to provide a durable assemblage,-and the front frame and bowl unit is tiltable upon the draft carriage 9 so as to either position the bowl bottom I3 within the cut as in Figs. 1 and 4, or to elevate the bowl II away from the ground. The auxiliary frame- 22 which is pivotally connected with the front frame 8 and bowl II by means of a transverse pivot pin 25, may likewise be formed of heavy metal plates or beams, and is swingable about the axis of the rear wheels 23 during raising and lowering of the bowl II and blade I4. The draft vehicle for propelling the scraper assemblage over the ground, is usually a tractor which is coupled to the front carriage 9; and the pump and control levers for actuating theseveral jacks I'I, 2I, 24, are ordinarily carried by the tractor near the operator's seat.

The improved front apron assemblage constituting the present improvement, is shown in detail in Figs. 2 and 3, and the rigid side arms I6 of the apron I5 are pivotally attached to the adjacent side walls I2 of the bowl I3 by means of pivot pins 26. The apron I5 may likewise be constructed of stiff metal plates welded or otherwise firmly united, and the lower portion of this apron is provided with a rearwardly inclined transverse blade 21 which is cooperable with the cutting blade I4 as shown in Fig. 1, in order to confine a load of earth 28 within the bowl IS. The front of the apron I5 has two laterally spaced flanges 29 rigidly attached thereto and projecting forwardly therefrom, and these flanges 29 have alined arcuate slots 30 therein, the front edges of which are reenforced by metal strips 3|. The apron I5 may be additionally reenforced by transverse stiffening plates 32, 33 and by a looped section 34 at the upper portion thereof, so as to provide an extremely rigid and durable apron assemblage.

While the improved apron I5 may be swung about its supporting pins 28 in any suitable manner, I prefer to utilize a hydraulic jack H as shown in Figs. 1, 4 and 5. The cylinder 35 of this jack I1 is pivotally suspendedjrom the ears I8 of the main frame 8, by means of trunnions 36; and the piston 31 is slidable within the cylinder 35 and preferably has its outer end provided with a roller pin 38 which is engageable with the slots 30 of the flanges 29.. With this cooperation existing between the jack I1 and the front apron I5, the apron will swing downwardly toward closed position asin Fig. 1, by gravity, with the pin 38 normally located in the upper ends of the slots 30, and when the Jack H is operated to elevate the apron I5, the piston pin 38 will remain in the upper slot ends. If, however,

the downward movement of the apron I5 byto undesirable pressures.

along the pin 38 to the position shown in Fig. 5.

During normal operation of the improved scraper assemblage, the draft carriage 9 is connected to a suitable traction vehicle, and the circulating pump located on the tractor is normally opera-ting to circulate liquid through the supply reservoir. The hydraulic jacks I1, 2|, 24 may then be operated independently of each other to either actuate the front and rear aprons I5, I9, or to elevate or lower the bowl I I and the scraper blade I4. When the various elements are positioned as shown in Fig. 4, and the assemblage is being moved along the ground, the bowl II is being loaded with earth 28 between the side walls I2, and the earth is piled up against the rear apron I9 as it proceeds along the bowl bottom I3. With the blade I4 incutting position, the bowl bottom I3 is disposed substantially parallel to the plane of cutting, and when the bowl II has been sufliciently loaded, the front apron I5 may be lowered to the position shown in Fig. 1, by causing the piston 31 of the jack I! to move outwardly with respect to the cylinder 35. The front apron I5 then drops by gravity due to its own weight, and if the lower portion of this apron should strike an obstruction and thus prevent gravity lowering of the apron, the piston pin 38 will move downwardly within the slots 30, and

if the previous movement of the apron has been insufficient, the pin 38 will engage the lower ends of the slots 30 and will forcibly lower the apron. After the front apron I5 has been thus lowered, the bowl II may be elevated and the load of earth 28 may be transported to any suitable dumping place.

When it becomes desirable to elevate the front apron I5 and to dump the load, the hydraulic jack I l may be manipulated to cause the piston 31 to move upwardly within the cylinder 35. The apron I5 will then be elevated by the Jack H to the position illustrated in Fig. 4, with the pin 38 in the upper ends of the slots 30. This will open the front of the bowl II to normal position. If, however, further elevation of the apron I5 is produced by engagement of the front of the apron with an obstruction and while the scraper is being drawn along the ground, the apron I5 will automatically swing upwardly to the position shown in Fig. 5, without subjecting the hoist I1 Such additional upward movement of the apron I5 is made possible by the slots 30 riding along the roller pin 33. When the obstruction has been passed, the apron I5 will again gravitate to the position shown in Fig. 4 preparatory to subsequent lowering thereon.

From the foregoing detailed description it will be apparent that the lost motion connection between the piston pin 38 and the apron I5, afforded by the tracks or slots 30, will permit the apron to move relatively to the hoist I'I without subjecting the latter to dangerous pressures. The lost motion is effective both during lowerin and'elevation of the apron I5, and the mechanismfor accomplishing-this lost motion is ODVI-I' ously extremely simple and has proven highly satisfactory in actual use. It is to be noted that while the tracks or guide slots 30- are curved. they are not generated about the axis of the pivot pins 26 as a center, but they are formed spirally relative to this axis so as to produce a cam action when cooperating with the roller pin 38. This is an important feature of the present invention in producing wide opening of the front apron as indicated by the showings in Figs. 4 and 5. The cam action produced by the special formation of the slots 30 provides for quick enlargement of, the opening without changing the position of the jack l1, so that the disposition of these slots is in fact very important. The entire front apron assemblage is very durable and rigid, and the apron is so formed that it will effectively confine the load within the bowl without permitting undesirable spilling. The long arm I6 about which the front apron I is swingable, also reduces the hydraulic pressure necessary in order to swing this apron about its pivot pins 26, and the improvement is readily applicable to scraper assemblages which have proven unsatisfactory in actual use.

It should be understood that it is not desired to limit this invention to the exact details of construction or to the precise mode of operation, herein shown and described, for various modifications within the scope of the claims may occur to persons skilled in the art.

I claim: I

ll. In a scraper, a transportable frame, a bowl rigidly suspended from said frame and having a front cutting blade, a front apron having side arms pivotally attached to the opposite side Walls of said bowl, a jack pivotally suspended from said frame and having a movable member cooperable with said apron to move the latter away from said blade, and slotted flanges carried by said apron and cooperating with said jack member to permit movement of said apron independently of said jack.

2. In a scraper, a bowl having a cutting blade, a front apronswingable toward and away from saidblade about an axis; an actuating jack for said apron pivotally suspended from said bowl, and a pin carried by said jack and coacting with a track on said apron, said track being formed to provide a dam action during movement of said pin therealong. a

3. In a scraper, a bowl having a cutting blade,

a front apron swingable toward and away from said blade about an axis, an actuating jack for said apron pivotally suspended from said bowl, and a roller pin carried by said jack and coacting with a slot on said apron, said slot being disposed spirally relative to said axis. I

4. In a scraper, a bowl having a cutting blade, an apron swingable relative to said blade about aflxed axis and having a curved slot disposed spirally of said axis,.and a jack for elevating said apron having a pin cooperable with said slot.

5. In a scraper, a bowl having a cutting blade, an apron swingable relative to said blade about an axis and having'a curved cam surface disposed spirally of said axis, and a jack having a cylinder pivotally suspended from said bowl and apiston movable-in said cylinder and provided with a pin cooperable with said cam surface to elevate said apron.

6. In a scraper, a frame having a cutting blade, an apron movable relative to said blade and having a curved slot therein, an actuating jack for said apron having a cylinder pivotally suspended from said frame and a piston movable within said cylinder toward and away from said apron, and

a pin carried by said piston and coacting with said slot.

7. In a scraper, a frame having a cutting blade, an apron swingable relative to said blade about an axis located rearwardly of the latter, said apron having a slot thereincurved' concavely relative to said axis, an actuating jack for. elevating said apron having a cylinder pivotally suspended from said frame in front of said blade and a piston movable within said cylinder toward and away from said apron, and a roller pin carried by said piston and'coacting with said slot.

8. In a scraper, a frame having a cutting blade, a front apron swingable about an axis relative to said blade, said apron having a curved slot disposed spirally relative to said axis, an actuating jack for said apron having one member pivotally suspended from said frame and another member movable in said pivoted member toward and away from said apron, and a pin coacting with said slot and with said movable member.

9. In a scraper, a transportable frame having a cutting blade suspended therefrom, a front apron swingable upon said frame about an axis located rearwardly of said blade and being mov able toward and away from the blade, said apron having rigid flanges provided with alined arcuate slots which are concave relative to said axis, and a jack having relatively longitudinally movable members one of which is pivotally suspended from said frame and the other of which has, a roller pin coacting with said slots.

10. In a scraper, a transportable frame having a cutting blade suspended therefrom, a front apron swingable upon said frame about an axis located rearwardly of said blade and being movable toward and away from the blade, said apron having rigid flanges provided with alined arcuate alined arcuate slots, and a jack havingrelatively movable members one of which is pivotally suspended from said frame and theother of which is movable toward and away from said apron and carries an end pin coacting with said slots.

12. In a scraper, a transportable frame having a transverse cutting blade, an apron swingable toward and away from said blade and having a slot curved transversely of its axis of swing, and a jack having rel ively movable members one of which is suspend from said frame and the other of which is movable toward and away from said apron and carries a pin coacting withsaid slot.

13. In a scraper, a transportable frame having a fixed transverse cutting blade, an apron swingable toward and away from said blade and having a slot disposed spirally relative to its axis of swing, and a jack having a plunger movable toward and away rom said apron and supporting a pin which coacts with said slot.

14. In a scraper, a transportable frame having a transverse cutting blade, an apron swingable about an axis toward and away from said blade and having a cam slot disposed spirally relative to said axis, a jack pivotally suspended from-said frame and having a plunger movable toward and away from said apron, and a roller pin carried by said plunger and coacting with saidslot.

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